Well, I've finally got all of the parts I neededto start modding up my KLX. I've got my 340 kit, Bill Blue carb, air filter, skid plate, and foot pegs. I was holding off until I got my exhaust, which showed up last week. Big Gun and Muzzy are really our only choices for full systems, and a few companies make slip-ons, but I decided to do something different (well, old school actually).

Even though Supertrapp doesn't list a slip-on for a KLX300, they will still make one if you special-order it. I have an IDS2 quite-core on my DR650 and I really like it, so I called Supertrapp directly and asked if they would make one for the KLX300. They obviously don't make anything for the KLX250s, so a KLX300was as close as I could get. Anyway, they said sure, they can build it, but it would take 6 - 8 weeks because it was a special order. The price was $243.00. I said build it.The part number is 611-6301.




I got the muffler, end-cap, mid-pipe, all of the mounting hardware, and the all-important disks. The disks are what make this exhaust cool. You can make it louder or quieter simply by adding or removing disks. The more disks you add, the less backpressure is created (and the louder it gets). I ordered a quite core though, which is not a straight-thru design. It still uses packing material, but it also has an internal baffle that keeps the noise down.





Each disk hasbolt holes that line up with the holes in the core and are bolted in. The last disk has no center hole, forcing the exhuast out between the disks. It also provides a built in spark arrestor.




I already had a KLX300 head pipe, but I wanted something like the FSW head pipe. I also wanted it in stainless steel like the stocker. So I took off the stock exhaust and started fabbing up my own head pipe. I used the bung off of the KLX300 head pipe and the mounting flange. I took the bung to work and had them machine the I.D. out. Then I got some 1 1/2" stainless tubing (1/16" wall) in various bends. I got way more tubing than I needed, just in case I screwed up.




The stock pipe was 1 1/4" I.D., while my tubing is 1 1/2". Here's the difference...





I started by mounting the Supertrapp exhaust, then used a 45 degree bend from its mid-pipe to get around the frame. I then cut one of the 180 degree bends in half, tack welded the bung on, and mounted it to the motor. The 180 degree bends had too large a radius, and I would have melted off my knee cap if I didn't narrow them up.




After lots of fitting and grinding, I used the other half of the 180 degree bend to fit the middle. I did all of the tack welding off of the bike, but the last one had to be done on the bike. The stuff around the pipe is called K-Wool, which is flame retardant and keepsweld splatter off of important things.




Here it is all tacked together and ready to be TIG welded. I'll be doing that at work (and after hours) tonight. Then all it needs is to be buffed out. Total cost of the whole system, including the slip-on, KLX300 head pipe, and the tubing was $367.00. So I did better than buying a full system, plus I got the enjoyment of making the head pipe myself.



I couldn't help myself -I fired it up, massive exhaust leaks and all. It has a real deep, "thumper" sound but doesn't have the crack of a race pipe when you rev it up. It's louder than stock, butnota lot more.You can talk to someone with it running without have to raise your voice much at all. Also, because it's built for the KLX300, it has the same issue with the right passenger footpeg as the Muzzy does.

Time to do some TIG welding...

 

So lemme get this straight, if I was to order the part number you have listed it would bolt up to my KLX300 headpipe?

 

Yep! It's actually built for the KLX300, so if you have a 300 head pipe, it will bolt right up. Like I said though, the right passenger footpeg hits the mid-pipe, so you will either have to do some grinding on the footpeg or take it off. Otherwise, there are no other issues.

 

I continue to be amazed at the creativity and can-do attitude on this forum! Nicely done on that head-pipe - great fabrication.

 

That supertrap can looks great with that end cap. I remember the older ones that didn't have that cap, just the disks showing. Never really cared for that look. Great work on the head pipe. Where did you order the tubing from?

 

Thanks for the kind words! I'm not done welding it yet, so there is stilltime for me to screw it up.

I got the tubing from a vendor at the Spring Carlisle Show (it's a giantclassic carand hot rod flea market). The vendor was Verocious Motorsports, and their website is http://vertexnow.com/Welcome-Verocious-Motorsports. I looked at their prices on their site, and I promise you that I didn't pay that much. I got 3 J-Bends (1 piece of tubing with a 180 degree bend and a 45 degree bend) for $76.00. The tubing is 1.5" O.D., 304 stainless steel.

 

nicce, would like to see more pictures once it's welded and finished! i'd like to see more exhaust options surface until i get a new one in about a year. keep up the good research/work!

 

Excellent Mod keep it up.

 

+1!

I've always liked the idea of being able to adjustthe back pressure. Epecially when you have a carb that is running way too lean and don't have the time to tear into it right away.

Excellent work! I'm lookingforward to seeing your heat shield solution. Tape would be anti-climactic at this point, so don't evenconsider it

 

id like to hear a sound clip! looks good man... is that tubing stainless? good work.